Focus your negotiation on the Total Cost of Ownership (TCO) rather than just the sticker price. Negotiate for an extended warranty (18-24 months), the inclusion of critical wear-and-tear parts, and free software updates for the PLC. If purchasing multiple units, request a volume discount of 5-10%. Additionally, clarify the Incoterms; for heavy machinery, CIF (Cost, Insurance, and Freight) or DAP (Delivered at Place) is often preferred to ensure the seller handles the complex logistics of heavy lifting and sea freight.